Add .gitignore, remove Xcode user data and .DS_Store

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,35 @@
+# macOS
+.DS_Store
+.AppleDouble
+.LSOverride
+
+# Xcode
+*.xcuserstate
+xcuserdata/
+*.xcworkspace/xcuserdata/
+DerivedData/
+*.moved-aside
+*.pbxuser
+*.mode1v3
+*.mode2v3
+*.perspectivev3
+*.xccheckout
+*.xcscmblueprint
+
+# Build output
+build/
+*.ipa
+*.dSYM.zip
+*.dSYM
+
+# Swift Package Manager
+.swiftpm/
+.build/
+
+# CocoaPods (not used here but keep for safety)
+Pods/
+
+# Secrets / env
+*.env
+.env.*
+secrets/